The Defender's Dilemma: Measuring AI Refusal on Real Incident Response Artifacts
Rahul Kumar · Team Rahul
Submitted to AI Incident Response Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
We tested whether AI models can help investigate AI-caused security incidents, or whether their own safety guardrails get in the way. Using 7 forensic analysis tasks built from real, publicly verified artifacts of the July 2026 Hugging Face intrusion including exploit code, infrastructure logs, and behavioral evidence, we tested 5 current models across neutral and incident-response-authorized framings. Claude Fable 5.1 blocked 92.9% of requests (13/14) via an API-level content filter before the model could generate a response. The other four models blocked zero and completed every task, including GPT-6 Astra from the same provider whose agents caused the incident. We also found an authorization paradox: adding professional incident-response framing causes Claude to block a prompt that it answers under neutral framing. On the hardest task, cryptographic weakness analysis, only Astra identified all vulnerabilities; open-weight models understood the code but missed the security flaws. The model that produces the strongest forensic analysis is also the one that blocks defenders from using it.
Reviews
The paper mentions a simple and useful case study showing that Claude Fable 5.1's content_filter blocked the most number of incident response requests, while other models in the evaluation did not. This finding could be a valuable data point for defenders. The limitations in the paper are also well documented. I really liked the C5 test where the author tried different wordings to see what triggered the block. However, it is not clear if the author tried something similar on the tasks that were blocked both ways, like in A1. That one has no attack words in the code, so the question is whether the code itself is what triggers the block or the words around it. This could be one of the future topics to discuss and expand on
The project provides a useful, focused benchmark of defensive analysis using public incident artifacts, with released responses and repeated checks of selected findings. Distinguishing API-level blocking from textual refusals is operationally valuable, and the framing-dependent blocking result deserves further investigation.
Cite this project
@misc{kumar2026defenders,
title = {{The Defender's Dilemma: Measuring AI Refusal on Real Incident Response Artifacts}},
author = {Rahul Kumar},
year = {2026},
month = sep,
note = {Submitted to AI Incident Response Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/the-defenders-dilemma-measuring-ai-refusal-on-real-incident-response-artifacts-ftid}},
url = {https://apartresearch.com/sprints/projects/the-defenders-dilemma-measuring-ai-refusal-on-real-incident-response-artifacts-ftid}
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